Assistant Chief Constable Tim Forber said it was not appropriate to speculate further at this stage, but revealed there would be a heightened police presence at this afternoon’s Barnsley game 'for reassurance’.

He said: “We understand that this morning’s incident will have been distressing and shocking for those in the town centre and wider Barnsley communities – rest assured we are working relentlessly to piece together what happened.

“A kitchen knife has been recovered by officers and is being forensically examined.

“At this stage, we are keeping an open mind as to the motivation. The investigation is being led by South Yorkshire Police but we are receiving support from detectives at Counter Terrorism Policing North East. It is not appropriate to speculate further.

“I’d urge anyone who witnessed this morning’s incident to get in touch with officers – if you hold any footage of the incident, we’d be really keen to speak with you as well.

“We’re in discussions with Barnsley Football Club ahead of this afternoon’s match – home and away fans are advised that there will be a police presence at the game and around the stadium to provide reassurance.

“I’d ask that the public continue to be vigilant and if you see anything that distresses you, or causes you concern, please report it to officers either in person or by calling 101. If a crime is in progress or a life is at risk, call 999 immediately.”